Introduction Normal splitting physiology inspiration creates a negative intrathoracic pressure this pulls more blood from the systemic venous circulation into the right heart this also holds more blood in the lungs as well leading to less blood going to the left heart this causes A2 to close earlier (less blood) and P2 to close later (more blood flow) increasing the splitting Wide splitting physiology a decreased ability of the RV to empty blood into the pulmonary circulation resulting in an exaggerated delay in pulmonic valve closure associated conditions states of delayed RV emptying Fixed splitting physiology shunting of blood from left to right that results in increased right heart volume resulting in a consistent delay in pulmonic valve closure can lead to pulmonary hypertension if large associated conditions ASD Paradoxical splitting physiology a decreased ability of the LV to empty blood into the systemic circulation resulting in a delayed closure of the aortic valve the left heart fills more during expiration so splitting occurs during expiration and P2/A2 move closer during inspiration associated conditions states of delayed LV emptying (e.g., aortic stenosis or left bundle branch block)